Why would I have oil circulating through my coolant in my radiator?

I know something is wrong by what exactly?Why would I have oil circulating through my coolant in my radiator?
looks like the transmission cooler inside the radiator has sprung a small hole(leak) common among automatics


oil cooler leak is common in turbochargers


If you do not have automatic or ruled out the leak then head gasket is blown or cracked blockWhy would I have oil circulating through my coolant in my radiator?
That is not a good sign! If it's engine oil that's in the cooling system, then it indicates that the engine head gasket is failing. The head gasket acts like a barrier between the engine oil and coolant so they don't mix while circulating to the engine head. If there is a break in the head gasket.... due to engine overheating.....between the oil feed port and the coolant port....that's when oil and coolant mix, therefore engine oil is discovered in the cooling system and vise versa....And coolant mixed with is not healthy for engine bearings....so have the head gasket done ASAP before further damage is done...





If transmission fluid is found in the coolant...the coolant will have more of a reddish color...transmission fluid is cooled by circulating it thru the radiator...yes, the coolant radiator....but the radiator is designed to share coolant and transmission fluid thru seperate channel inside....if there is a rupture inside the radiator then these two fluid mixes....and that not good either cause u now have coolant and trans. fluid mixing in the transmission! Transmissions are not cheap to replace either...so replace that radiator soon before it's too late.
Something is ';wrong';? Yes, I'd agree! You have a blown head gasket, cracked cylinder head, or cracked engine block. The gasket can ve replaced relatively inexpensively, the head could be replaced (at great expense) and the engine as well (at even greater expense), but only you know if it's worth the cost. You can't sell a car with a cracked engine block (by law), so don't even think of selling it to some poor unsuspecting schnook.





Could also be a minor problem like transmission coller leaks, but since you said ';oil';, I presume you mean engine oil and not transmission fluid.
Either your oil cooler is bad or a head gasket. Depends on make of vehicle if it has an oil cooler or not. If it doesn't it is a head gasket.